In non-psych speak, that's simply the preference for immediate
over future rewards — from choosing to eat a cupcake now over
fitting in your jeans later to spending $500 on a new TV instead
of saving that cash for future use.

When Olin Business School researchers Gubler and Pierce found that workers who
contributed to their companies' 401(k) plans tended to be the
same ones who proactively improved their health, they suspected
that time discounting might play a role. Perhaps the same
employees who were better able to combat the discounting in
regard to their financial future could do the same for their
long-term health.

In another paper, "Time Discounting and Time Preference: A Critical
Review," Shane Frederick, George Loewenstein, and Ted
O'Donoghue point out that time discounting may be common among
people who "find it painful to delay gratification" — even more
so when the thing they want most is right there in front of them.
Anyone who has overturned their budget for a suite of
Apple products will identify with that.

The tricky thing about time discounting is there isn't really a
way to keep yourself from doing it. Scary stats, like the fact
that some experts predict a retiree will need $2 million in savings, and persuasive charts,
like the ones that illustrate the power of compound interest, only go so far.

Luckily, you don't need urgency to be an effective saver. Setting
up a simple automatic contribution from your paycheck to your
401(k) or IRA — or both — will take the hard part out of your
hands. You can keep buying whatever tempting gadgets cross your
path while your money goes on working behind the scenes,
preparing for whatever your future self needs.